molstar
Version:
A comprehensive macromolecular library.
95 lines (94 loc) • 2.59 kB
JavaScript
;
/**
* Copyright (c) 2017-2021 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author David Sehnal <david.sehnal@gmail.com>
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.hash1 = hash1;
exports.hash2 = hash2;
exports.hash3 = hash3;
exports.hash4 = hash4;
exports.hashString = hashString;
exports.cantorPairing = cantorPairing;
exports.sortedCantorPairing = sortedCantorPairing;
exports.invertCantorPairing = invertCantorPairing;
exports.hashFnv32a = hashFnv32a;
// from http://burtleburtle.net/bob/hash/integer.html
function hash1(i) {
let a = i ^ (i >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
function hash2(i, j) {
let a = 23;
a = (31 * a + i) | 0;
a = (31 * a + j) | 0;
a = a ^ (a >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
function hash3(i, j, k) {
let a = 23;
a = (31 * a + i) | 0;
a = (31 * a + j) | 0;
a = (31 * a + k) | 0;
a = a ^ (a >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
function hash4(i, j, k, l) {
let a = 23;
a = (31 * a + i) | 0;
a = (31 * a + j) | 0;
a = (31 * a + k) | 0;
a = (31 * a + l) | 0;
a = a ^ (a >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
function hashString(s) {
let h = 0;
for (let i = 0, l = s.length; i < l; i++) {
h = (h << 5) - h + s.charCodeAt(i) | 0;
}
return h;
}
/**
* A unique number for each pair of integers
* Biggest representable pair is (67108863, 67108863) (limit imposed by Number.MAX_SAFE_INTEGER)
*/
function cantorPairing(a, b) {
return (a + b) * (a + b + 1) / 2 + b;
}
/**
* A unique number for each sorted pair of integers
* Biggest representable pair is (67108863, 67108863) (limit imposed by Number.MAX_SAFE_INTEGER)
*/
function sortedCantorPairing(a, b) {
return a < b ? cantorPairing(a, b) : cantorPairing(b, a);
}
function invertCantorPairing(out, z) {
const w = Math.floor((Math.sqrt(8 * z + 1) - 1) / 2);
const t = (w * w + w) / 2;
const y = z - t;
out[0] = w - y;
out[1] = y;
return out;
}
/**
* 32 bit FNV-1a hash, see http://isthe.com/chongo/tech/comp/fnv/
*/
function hashFnv32a(array) {
let hval = 0x811c9dc5;
for (let i = 0, il = array.length; i < il; ++i) {
hval ^= array[i];
hval += (hval << 1) + (hval << 4) + (hval << 7) + (hval << 8) + (hval << 24);
}
return hval >>> 0;
}